luban 0.4 for python3

[linjiao]

Dear Friends,

A new version of luban has made good progress. This version only works
for python3 at this moment, because a lot of "meta-programming" and
some syntactic sugar are implemented using python3's more powerful
meta-class machineries.

The main improvements in this version is that this version makes it
much more explicit and easy to extend luban "UI specification
language", which I will try to explain in more details in the new
documentation. This improvement will benefit mostly "UI framework
developers", who develop UI framework for UI developers. Another major
improvement is the structure of luban UI projects is now much simpler.
In the previous versions we had luban actors and visual factories as
pyre components that are odb files, and that could be quite difficult
for novice users to swallow. Now we have all of them as just python
modules. This improvement should benefit UI developers.

Starting this version, luban is structured to have a very lean core (a
few concepts, a couple of widgets, actions and events), and a default
extension. This makes it much clearer for ui framework developers to
understand what is the most essential part of UI.

The status of this development: the core of luban is ready. The
default extension (named "tiimber") is more than 50% done, and
"aokuang", the testing framework for luban core and luban extensions,
is near complete. There are still a lot todo in my mind:

* finish timber by adding more widgets (and add tests in
aokuang.timber for each new widget)
* implement in timber the "data store" (still wondering if it should
be in the core or in the timber extension...)
* documentation: tutorials. we need much better tutorials at this
stage so users can follow them easily.
- explain the key concepts
- tutorials for ui developers
- tutorials for ui framework developers (writing a new extension, or
extend an existing extension)
* implement some scaffolding so users can create a luban ui project
easily (0.2 has quite a bit scaffolding code that we can reuse)
* examples: function plotter, "jazz club" ...
* wx implementation
* gongshuzi

The repository for the new version is a bzr one. Anyone interested in
working on improving luban please send me your ssh public key to gain
access. I need a lot of your help to make quick progress on luban!

Let me know!

cheers,
Jiao